Safety monitoring system for punch press operators

ABSTRACT

This safety monitoring system for punch press operators is designed to prevent the operators from being injured by such presses or other factory equipment. Primarily, it consists of a pair of wrist units which are strapped to the wrists of the operators, and which include optical fiber cables and a latching assembly, and the optical fiber cables are used in cooperation with a pair of identical electronic circuits employing LED&#39;s, a light sensitive transistor, a pair of other transistors, a zener diode, and a relay, for instantly shutting a punch press on or off.

This invention relates to machine safety devices, and more particularly,to a safety monitoring system for punch press operators.

The principal object of this invention is to provide a safety monitoringsystem for punch press operators, which will be so designed, as toprevent a punch press operator from getting the hands or fingers injuredin the pinch areas of punch presses.

Another object of this invention is to provide a safety monitoringsystem for punch press operators, which will be unique, in that it willbe an improvement over the prior art. Presently, pull back systems areonly effective when they are being worn, and the punch press may beoperated whether the pull back system is being worn or not. The presentinvention prevents the machine from operating unless the wrist unitsthereof are buckled, and properly in place.

A further object of this invention is to provide a safety monitoringsystem for punch press operators, which will include monitoringcircuits, which, when the wrist units are properly mounted on theoperator's wrist, are completed, thus enabling the machine to operate.

A still further object of this invention is to provide a safetymonitoring system for punch press operators, which will have fail-safemeans, will have no electrical voltages at the operator's wrists, theoptical cable thereof cannot be shorted, jumped, or spliced together,and, if the cable fails, it cannot be twisted or spliced together. Evenfurther, it will be light in weight, will not impede the operator, oradd to job complexity, and there will be no reduction or loss ofproduction time when operating the punch press.

Other objects are to provide a safety monitoring system for punch pressoperators, which is simple in design, inexpensive to manufacture, ruggedin construction, easy to use, and efficient in operation.

These, and other objects, will be readily evident, upon a study of thefollowing specification, and the accompanying drawing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of the present invention;

FIG. 2 is a plan view of one of the wrists units of the invention;

FIG. 3 is a view taken along the line 3--3 of FIG. 4;

FIG. 4 is a fragmentary cross-sectional view of the optic cablestructure of the invention;

FIG. 5 is a top plan view of the circuit package of the invention;

FIG. 6 is a schematic wiring diagram of the circuit of the presentinvention;

FIG. 7 is a bottom plan view of the housing mechanism of the invention;

FIG. 8 is a side elevational view of FIG. 7;

FIG. 9 is a view taken along the line 9--9 of FIG. 8, and is illustratedrotated ninety degrees clockwise;

FIG. 10 is a cross-sectional view, taken along the line 10--10 of FIG.9, and illustrates the latch and buckle tongue in the locked condition,and

FIG. 11 is a cross-sectional view similar to FIG. 10, but illustratingthe latch and buckle tongue in unlocked condition.

DESCRIPTION OF PREFERRED EMBODIMENTS

Accordingly, a system 10 is shown to include a wrist unit 11 forattachment to the operator's hand, an electronic package or unit 12having circuit 14 therein, which is coupled to wrist unit 11, and themachine control equipment 14a, which is coupled to the punch press 15 orother factory machine. Two of the wrist units 11 are required, one foreach hand 13 of the press 15 operator, and one electronic package orunit 12 is required for each wrist unit 11. Each unit 11 includes ahousing 16, having a rectangular eye 17, suitably fixedly secured to oneside, and a buckle 18 is similarly secured to the opposite side, forremovably and adjustably receiving a web strap 19, having openings 20therethrough, for its adjustment. A second strap 21 is provided, and isfixedly secured, at one end, to strap 19 in a suitable manner, and itsopposite end is suitably fixedly secured to ring 24, and ring 22, for aperson's pull-cable 22a, is received within openings 23 of housing 16,by means of bar 24a. Strap 21 is received between the thumb andforefinger of the operator's hand 13, and strap 19 is fastened aroundthe wrist of the operator for proper operation of system 10. The buckletongue 18a is one of the key factors in the operation of system 10,which hereinafter will be described. The base 25 of unit 11 includes acover 26, which is suitably fixedly secured to base 25. Optical fibercables 27 and 27c are bonded to the interior of unit 11 in a suitablemanner, and are separated by gap 27d, and Buckle tongue 18a is pivotallyreceived upon a shaft or pin 28, which is fixedly secured across opening29 in base 25, and the projection 30, which is integrally attached totongue 18a, provides for engagement with one side of an "E"-shaped wirespring 31 within recess 32. One end of spring 31 is rounded, and isreceived within cut-out 33 of a projection 34, jutting inward of oneside of base 25, and is integrally attached thereto, for retainingspring 31. Looking now particularly at FIG. 10 of the drawings, there isillustrated the locked condition of unit 11, by the wrist strap 19 beingengaged with the buckle 18 and the buckle tongue 18a. In this instance,one leg of spring 31 engages in the lower cut-out notch 35 in one edgeof the latch 36. Latch 36 is freely and slideably received withinopening 37 through base 25 and cover 26. Latch 36 is provided with acircular base (a pressure plate) 38 which is integrally attachedthereto, and serve to engage with one end of a pair of coil springs 39received within openings 40 in base 25. A rubber diaphragm 41 includesan integrally attached annular projection 42, which is frictionallyreceived within a similar-shaped cut-out 43a in base 25, and diaphragm41 engages with latch 36 at its bottom end, and the opposite ends ofsprings 39 engage with the bottoms of openings 40, so as to urge latch36 to its normal upward position. An aperture 43 is provided throughlatch 36, and with aperture 43 in the position shown in FIG. 10, lightcan be transmitted therethrough, by means of the optic fiber cables 27and 27c. Semicircular grooves 44 in base 25 and insert serve as recessmeans for receiving cables 27 and 27c. The ends of cables 27 and 27c aresecured within threaded couplings 27a, and by screw fasteners 27b.

The circuit 14 includes a light emitting diode 45, the light of which isdirected upon the optic fiber cable 27, and this light produced istransmitted, via cable 27, to the aperture 43. LED 45 is coupled acrosswires 46 and 47, which are connected to a twelve volt power supply (notshown). A pair of resistors 48 and 49 are coupled across wires 46 and47, and are in series with LED 45, and a zener diode 49 is coupledacross LED 45 and resistor 49, for limiting current flow. A lightsensitive transistor 50 is also coupled across wires 46 and 47 by itscollector 51 and its emitter 52, the emitter 52 being coupled to thenegative side of the power supply, and the collector 51 being coupled inseries with resistors 53 and 54. The base 55 of a second transistor 56is coupled between resistors 53 and 54, and the emitter 57 is coupled tothe positive wire 46 of circuit 14. The collector 58 of 56 is coupled inseries with resistors 59 and 60, which are coupled to the negative orground wire 47, and the base 61, of a third transistor 62, is coupledbetween resistors 59 and 60. The collector 63 of 62 is coupled with aresistor 64 to the base 55 of transistor 56, and the negative side of arelay 65 is coupled between resistor 64 and collector 63 of 62, theemitter 66 of transistor 62 being coupled to the negative or wire 47 ofcircuit 14. The contacts 67 of relay 65 are coupled in series with thecontrol circuit or circuits of the machinery, which are not shown.

In operation, each wrist unit 11 is placed on the operator's hands bythe fingers being inserted within the confines of the straps 21, andstrap 19 is then passed through buckles 18 thereof, and fastened bymeans of buckle tongues 18a and openings 20. When properly mounted onthe wrists, the monitoring circuits 14 are completed, thus enabling thepunch press 15 or other equipment to operate. The abovementioned isaccomplished by moving the latch 36 of each unit 11, by wrist pressure,from an unlatched condition to a latched condition, which is when thewrist strap 19 is captured, and holding the buckle tongue 18a againstthe buckle 18, which moves the latch spring 31 to lock the latch 36 inposition in the lower notch 35. With the latch 36 in the abovementionedposition, light from LED 45 is transmitted through aperture 43 by cable27 means. This transmission energizes the circuits 14, and permits thepress 15 to operate.

Two motions are required to set system 10. The first is the moving up oflatch 36, and the second is permitting the buckle tongue 18a to move thelatch spring 31 into an extended and latch locked condition, and shouldthe buckle 18 be released, the latch spring 31 will automaticallyrelease the latch 36 to its normal position, and the mechanicaloperation of attaching the wrist units 11 sets up the operation of theelectronic and electrical system, plus the optical components.

With the twelve volt power supplied to the circuits 14, the LED 45 ofeach directs light upon the optical cable 27, and this light by cable 27is transmitted to the aperture 43. With the latch 36 in the elevatedposition, the light will pass to the other portion of the optic cable27, and will be conducted to the light sensitive transistor 50.Transistor 50 causes transistor 62 to function, which causes relay 65 tobe actuated, which causes the press 15 or other equipment to operate,and any event which interrupts the light source, or blocks the lightsource, will cause the press 15 or other equipment to stop operating,and it shall be noted, that all of the light is contained within theoptic cables 27, or the attaching hardware.

While various changes may be made in the detail construction, it isunderstood that such changes will be within the spirit and scope of thepresent invention, as is defined by the appended claims.

What I now claim is:
 1. A passive safety monitoring system for pressoperators, comprising in combination:a wrist mountable unit containingmechanism which controls light passage through two optical fiber cablessecured to said wrist mountable unit when the wrist unit is properlypositioned on the wrist of the operator; a separate electronic unitwhich initiates light passage through one of the optical fiber cables tothe wrist unit and, also, receives light through the second opticalfiber cable from the wrist unit completing a light transmission circuitto activate additional electronic circuitry in the electronic unit toenergize press control circuits; a press operating system activated bythe press control circuits in said additional electronic circuitry. 2.The combination as set forth in claim 1 wherein said wrist unit is oneof a pair for each wrist of the press operator, said electronic unitcontains light transmitting and receiving circuitry for each of saidwrist units of the pair and said wrist unit is secured to the wrists ofthe operator by a pair of straps.
 3. The combination as set forth inclaim 2 wherein said wrist unit includes:a wrist mountable unit base; afirst strap receiving eye fixedly secured to one side of the wrist unitbase; a first strap receiving buckle secured to the wrist unit baseopposite to said first strap receiving eye; a first adjustable strapaffixed to said strap receiving eye wherein said first strap receivingbuckle removably receives said first adjustable strap which is fixedlysecured to said first strap receiving eye at one end to bind the wristunit to the wrist of the operator; a second strap fixedly secured at oneend to said first adjustable strap and the other end to the wrist unitbase between the first strap receiving eye and first strap receivingbuckle by means of a first ring fixedly secured to the wrist unit baseso as to define a hole in said second strap through which the operatorplaces the thumb when affixing said wrist unit to the wrist; a secondring fixedly secured to said wrist unit base opposite the first ring towhich is attached a press pull back cable.
 4. The combination as setforth in claim 3 wherein said wrist unit base contains means forinterrupting light transmission through the optical fiber cablescomprising:a buckle tongue pivotally engaged in said wrist unit base; aprimary spring means within said wrist unit base having its movementcontrolled by said buckle tongue; a latch means engaged to said primaryspring means and slidable within an opening in said wrist unit base saidlatch means having a circular base integrally attached thereto; a lighttransmitting aperture within said latch means; a second spring means inthe wrist unit base in contact with the circular base which secondspring means along with the primary spring means controls movement ofthe latch means and light transmission via the first and second opticalfiber cables through the latch aperture when the wrist unit is properlypositioned on the wrist which light transmission then permits activationof the press through an electronic unit and when the wrist unit is notproperly positioned on the operator's wrist the latch means aperture ismovably disengaged from the light transmission mode by the action ofboth the primary and secondary spring means to effect deactivation ofthe press operating system.
 5. The combination as set forth in claim 4wherein a flexible dust inhibiting diaphragm is in direct contact withthe latch mechanism circular base which diaphragm includes integrallyattached annular projections frictionally mounted in cutouts in the baseof the wrist unit.
 6. A wrist-mountable unit for use as part of apassive safety monitoring system which comprises:(a) a wrist unit basestructure having light optical fiber cable receiving means on the wristbase, for connection toa first optical fiber cable for lighttransmission from a separate light transmitting electronic unit, asecond optical fiber cable for light transmission through and from saidwrist unit base back to said separate light transmitting electronic unitto complete a light transmission circuit through said wrist unit base,said wrist unit base structure (a) having a mechanical lighttransmission control means which includes: (a) a buckle tongue pivotallyengaged within said wrist unit base with (b) a primary spring meanswithin said wrist unit base having said primary spring movementcontrolled by an operator's action on said buckle tongue, (c) movablelatch means containing a light transmitting aperture within said wristunit, said latch means engaged with said primary spring means withinsaid wrist unit and slideable within an opening of the wrist unit base,to control the transmission of light through the aperture thereof, andsaid latch means having a circular base integrally attached thereto, and(d) a second spring means housed in said wrist unit base in pressurecontact relation to said latch means circular base so that when thewrist unit is properly positioned on the press operator's wrist bypositioning action of the buckle tongue, the primary spring, thecircular base and the secondary spring, the aperture of the latchbecomes movably positioned so that the latch aperture becomes alignablewith the first and second optical fiber cables to permit lighttransmission through the first optical fiber cable, the aperture of thelatch within said wrist unit base and into the second optical fibercable to complete the light transmission circuit to the electronic unit,and when the wrist unit is not properly attached to the press operator'swrist, the light transmitting aperture in said latch means is movablydisengaged from its light transmitting position by the action of boththe primary and secondary spring means within said wrist unit, so thatthe latch aperture no longer permits light transmission through theoptical fiber cables to deactivate the press operating system.